The invention relates to allocating channels of a wireless network and offering services to terminals of the wireless network. The invention relates especially to utilising group transmissions in a wireless network. The invention is suited especially, but not limited to, for wireless networks with a limited bandwidth for multicast transmissions.
A problem underlying the invention is that in wireless networks, such as in mobile telephone networks, the overall bandwidth is limited and usually reserved by one single mobile terminal per channel, and altogether the number of channels in the network is limited. Also, at the moment services, such as phone calls or data calls over a mobile telephone network, are rather expensive. One improvement is a so called packet radio network, such as GPRS (General Packet Radio Service) which uses packet transmission, where channels are reserved dynamically whereby the channel is reserved by a certain mobile telephone only when there is something to transmit. However, for certain high load services this is still not a solution. In future there is a need to provide more and more services to a mobile terminal. Certain such services are real-time services, such as radio and television broadcasts, in which information is transmitted continously without pauses and to use a mobile network for such transmissions, even with packet radio, would end up being very expensive for the subscriber. This is due to the fact that the mobile network has been designed for point-to-point services and transmissions. Thus a user would not be very likely to use services, such as receiving a radio or TV broadcast, over a mobile telephone network. And mobile network bandwidth would not easily accommodate a significant number of such users.
Accordingly, it is an object of the present invention to provide a mechanism for allocating channels of a wireless network for transmitting services to different subscribers, i.e. terminals of the wireless network.
According to a first aspect of the invention there is provided a method for offering services to subscriber terminals of a wireless communication network, the method being characterized in that it comprises
allowing the users of the subscriber terminals to select between a first service to be transmitted as a point-to-point individual transmission to the subscriber terminal over the wireless network and a second service to be transmitted as group transmission to the subscriber terminal over the wireless network.
According to a second aspect of the invention there is provided a method of allocating channels of a wireless network, the method being characterized in that it comprises
allocating a first subset of the channels to individual point-to-point user channels having a single recipient, and
allocating a second subset of the channels to group channels being capable of having multiple recipients.
According to a third aspect of the invention there is provided a network element for assisting allocation and transmission of a service from a server to at least two subscribers in a network, the network element being characterized in that it comprises:
means for keeping information on available services,
means for receiving requests from subscriber terminals of a wireless network for one of said available services,
means for configuring transmission of the service over one of a group transmission and an individual point-to-point transmissions, the transmission mode being dependent on at least one of the particular service requested and information on preferred transmission mode in the request transmitted by the subscriber terminal.
According to a fourth aspect of the invention there is provided a communication device for receiving an allocated service via a wireless network having a number of channels for communication over the air interface, the communication device being characterized in that it comprises:
means for selecting between a first service to be transmitted as a point-to-point individual transmission to the subscriber terminal over the wireless network and a second service to be transmitted as group transmission to the subscriber terminal over the wireless network, and
a transceiver for sending a request to receive one of the first and second service as a response to a performed selection.
According to a fifth aspect of the invention there is provided a system comprising a server for providing a service, a wireless network for communicating said service in channels over an air interface, and terminals of said wireless network for receiving the service in a channel over the air interface, the system being characterized in that it comprises
a first subset of the channels allocated to individual point-to-point user channels having a single terminal as recipient, and
a second subset of the channels allocated to group channels being capable of having multiple terminals as recipients.
The invention deals with how the total transmission bandwidth is allocated between different purposes when transmitting services via networks. In one embodiment of the invention subscribers transmit requests to service providers including information on what kind of services they want to use, and the requests also contain information about on how the requested service is to be transmitted to the subscribers. The service can be transmitted as a group transmission or as one or more individual (point-to-point) transmissions. With xe2x80x98individualxe2x80x99 or xe2x80x98point-to-pointxe2x80x99 transmission is meant that each data packet is dedicated to only one mobile node, such as mobile phone. xe2x80x98Group transmissionxe2x80x99, as used herein, is a generic term for techniques in which data packets are intended to a group comprising two or more subscribers. Broadcasting and multicasting are common examples of group transmissions.
One purpose of the invention is to allow service offering of real time radio or TV braodcasts in a cost effective way, which lowers per subscriber cost while still maintaining or even increasing the revenue level of the operator. In this use a subscriber joins an existing group, where group formation usually happens at the source of the transmission.
In a further embodiment of the invention, group transmission is used to decrease the network capacity usage (and thus to increase network capacity) of large content file downloads by offering the download in predefined intervals for subscribers who have requested the service during the same period. In this case the acceptance by the subscriber of joining a group transmission may cause some delays. Namely, it is highly unlikely that a large group of subscribers will request a service simultaneously. This means that for certain type of services, group formation will involve delays, whereas for other services (such as radio broadcast) there is no delay, but a subscriber will be joined to the service immediately. Some applications and some subscribers tolerate longer delays than others. The subscribers should be able to indicate that they are willing to join a group if joining the group causes a certain maximum delay and/or allows a certain minimum price deduction over point-to-point transmission.
According to a preferred embodiment of the invention, this problem (delays and price issued versus subscriber preferences) is solved by requests sent by subscribers or evaluating subscription profiles which indicate on what terms each mobile node subscriber is willing to suffer additional delays. The contents of the profiles differ between different application types. For example, a file download may, in some situations, tolerate delays up to some hours. In contrast, an investor may not be willing to wait more than a few seconds for an important piece of news. Thus, the network operator or server administrator may set up network-wide or server-wide default profiles which indicate the maximum allowable delay for each application type. The profiles may also differ between different subscribers. The subscriber-specific profiles override the network-wide or server-wide default profiles. Yet further, a subscriber should be able to indicate if a certain situation requires a deviation from the subscriber-specific profile, which in turn indicates a deviation from the network-wide or server-wide default profiles. Such a temporary deviation can be indicated by including a corresponding parameter in the actual service request.
Subscribers inform the service providers by various requests. The requests comprise information about the requested information and information about a preferred transmission mode. In addition to the information requests, the history of the service popularity and/or the type of the service can be taken into account in e.g. when and for how many subscribers a group is formed. For example, for some service types, a group can be formed for a single subscriber, and more subscribers can be added to the group later. An example of such a service is file download, if the download protocol allows the download to begin at an arbitrary position of the file. Another example is real-time video wherein the subscriber wants to see what is happening now, instead of requesting transmission from the beginning of the program. (Some video sources do not even have a xe2x80x98beginningxe2x80x99. For example, ski resorts or golf courses may offer real-time video of the current weather conditions.) With such services, if the history shows that the service has been popular, a group may be formed although it initially comprises only one subscriber. Some basic services, such as authority information, can be always transmitted to subscribers independently of the requested services or allocated resources. Thus, the system reserves a minimum resource being capable of transmitting the authority information at the request.
The air interface capacity is limited. The bandwidth usage may be divided in different priorities. Therefore the service provided to the users can be delayed or even cancelled, e.g. if the service needed is not so important and the user would not pay so much about the service, especially if the bandwidth is limited by usage for important connections. Service may also be cancelled in a roaming situation where the terminal device moves under an adjacent transmitter, such as an adjacent base station, and that transmitter does not have enough free capacity for this purpose. Basically in business sense there may be two different kind of services: point-to-point and point-to-multicast. The point-to-point is normal individual usage of bandwidth, like when having connection to the phone calls, and usually the user cannot influence to the costs. The point-to-multicast transmission can be divided into the different categories depending what kind of services the user is interested in.
There are two different cases of group forming: 1) The traditional case of broadcasting applications, e.g. TV or radio, where a transceiver is joined to a real-time multicast transmission as soon as the request arrives. 2) The service is e.g. retrieval of a file type copy such as an individual audio or video file, whereby a multicast group can be formed based on timeslots of arriving requests.